Atmospheric-Absorption Adjustment Procedure for Aircraft Flyover Noise Measurements.

Abstract

An analytical method was developed for adjusting measured aircraft noise levels for differences in atmospheric absorption between test and reference meteorological conditions along the sound propagation path. The method is based on the procedure in the proposed American National Standard ANS S1.26 for calculating pure-tone sound absorption as a function of the frequency of the sound and the temperature, humidity, and pressure of the air. Measured aircraft noise levels are assumed to be 1/3-octave-band sound pressure levels. A computer program was written in FORTRAN IV to carry out the calculations. The operation of the computer program, the required input data, and all symbols and terms used in the program are described. A program listing of source statements is provided. Recommendations are given for applying the method to routine processing of aircraft noise measurements. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1977
Accession Number
ADA051700

Entities

People

  • Alan H. Marsh

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Absorption Coefficients
  • Acoustic Propagation
  • Air Force
  • Air Pressure
  • Aircrafts
  • Ambient Noise
  • Atmospheric Attenuation
  • Barometric Pressure
  • Computer Programs
  • Computers
  • Data Processing
  • Frequency Bands
  • Lapse Rate
  • Mach Number
  • Plastic Explosives
  • Pressure Measurement
  • Sea Level

Fields of Study

  • Environmental science
  • Physics

Readers

  • Acoustics.
  • Computer Science.
  • Spectroscopy.